1. Field
Example embodiments of inventive concepts relate to a method of operating a memory controller, and/or a memory system, a memory card and a portable electronic device including a memory controller.
2. Description of the Related Art
Memory devices may be classified into volatile memory devices and nonvolatile memory devices. Volatile memory devices lose data when the power supply is turned off. On the other hand, nonvolatile memory devices retain data even when the power supply is turned off.
Examples of nonvolatile memory devices include read-only memories (ROMs) and electrically erasable programmable read-only memories (EEPROMs).
The structure and operation of flash memory devices introduced as flash EEPROMs are different from those of conventional EEPROMs. A flash memory device may perform an electronic erase operation on a block-by-block basis and a program operation on a bit-by-bit basis.
Threshold voltages of programmed memory cells included in a flash memory device may change due to various causes, including floating gate coupling and charge loss over time. Thus, a change in the threshold voltages of the memory cells may undermine the reliability of read data.